21 research outputs found

    The Far-Ultraviolet "Continuum" in Protoplanetary Disk Systems II: CO Fourth Positive Emission and Absorption

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    We exploit the high sensitivity and moderate spectral resolution of the HSTHST-Cosmic Origins Spectrograph to detect far-ultraviolet spectral features of carbon monoxide (CO) present in the inner regions of protoplanetary disks for the first time. We present spectra of the classical T Tauri stars HN Tau, RECX-11, and V4046 Sgr, representative of a range of CO radiative processes. HN Tau shows CO bands in absorption against the accretion continuum. We measure a CO column density and rotational excitation temperature of N(CO) = 2 +/- 1 ×\times 1017^{17} cm2^{-2} and T_rot(CO) 500 +/- 200 K for the absorbing gas. We also detect CO A-X band emission in RECX-11 and V4046 Sgr, excited by ultraviolet line photons, predominantly HI LyA. All three objects show emission from CO bands at λ\lambda >> 1560 \AA, which may be excited by a combination of UV photons and collisions with non-thermal electrons. In previous observations these emission processes were not accounted for due to blending with emission from the accretion shock, collisionally excited H2_{2}, and photo-excited H2; all of which appeared as a "continuum" whose components could not be separated. The CO emission spectrum is strongly dependent upon the shape of the incident stellar LyA emission profile. We find CO parameters in the range: N(CO) 101819^{18-19} cm2^{-2}, T_{rot}(CO) > 300 K for the LyA-pumped emission. We combine these results with recent work on photo- and collisionally-excited H2_{2} emission, concluding that the observations of ultraviolet-emitting CO and H2 are consistent with a common spatial origin. We suggest that the CO/H2 ratio in the inner disk is ~1, a transition between the much lower interstellar value and the higher value observed in solar system comets today, a result that will require future observational and theoretical study to confirm.Comment: 12 pages, 7 figures, 3 tables. ApJ - accepte

    A Far-ultraviolet Atlas of Low-resolution Hubble Space Telescope Spectra of T Tauri Stars

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    We present a far-ultraviolet (FUV) spectral atlas consisting of spectra of 91 pre-main sequence stars. Most stars in this sample were observed with the Space Telescope Imaging Spectrograph (STIS) and Advanced Camera for Surveys (ACS) on the \emph{Hubble Space Telescope} (\emph{HST}). We find strong correlations among the \ion{O}{1} λ\lambda1304 triplet, %\ion{C}{2} λ\lambda1335, the \ion{Si}{4} λλ\lambda\lambda1394/1403 doublet, the \ion{C}{4} λ\lambda1549 doublet, and the \ion{He}{2} λ\lambda1640 line luminosities. For classical T Tauri stars (CTTSs), we also find strong correlations between these lines and the accretion luminosity, suggesting that these lines form in processes related to accretion. These FUV line fluxes and X-ray luminosity correlate loosely with large scatters. The FUV emission also correlates well with Hα\alpha, Hβ\beta, and \ion{Ca}{2} K line luminosities. These correlations between FUV and optical diagostics can be used to obtain rough estimates of FUV line fluxes from optical observations. Molecular hydrogen (H2_{2}) emission is generally present in the spectra of actively accreting CTTSs but not the weak-lined T Tauri stars (WTTSs) that are not accreting. The presence of H2_2 emission in the spectrum of HD 98800 N suggests that the disk should be classified as actively accreting rather than a debris disk. The spectra in the atlas are available at http://archive.stsci.edu/prepds/ttauriatlas.Comment: 89 pages, 30 figures, published in Ap

    Modelling human choices: MADeM and decision‑making

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    Research supported by FAPESP 2015/50122-0 and DFG-GRTK 1740/2. RP and AR are also part of the Research, Innovation and Dissemination Center for Neuromathematics FAPESP grant (2013/07699-0). RP is supported by a FAPESP scholarship (2013/25667-8). ACR is partially supported by a CNPq fellowship (grant 306251/2014-0)

    How Religion, Social Class, and Race Intersect in the Shaping of Young Women’s Understandings of Sex, Reproduction, and Contraception

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    Using a complex religion framework, this study examines how and why three dimensions of religiosity—biblical literalism, personal religiosity, and religious service attendance—are related to young women’s reproductive and contraceptive knowledge differently by social class and race. We triangulate the analysis of survey data from the Relationship Dynamics and Social Life (RDSL) study and semi-structured interview data from the National Study of Youth and Religion (NSYR) to identify and explain patterns. From the quantitative data, we find that all three dimensions of religiosity link to young women’s understandings of sex, reproduction, and contraception in unique ways according to parental education and racial identity. There is a lack of knowledge about female reproductive biology for young women of higher SES with conservative Christian beliefs (regardless of race), but personal religiosity and religious service attendance are related to more accurate contraceptive knowledge for young black women and less accurate knowledge for young White women. From the qualitative data, we find that class and race differences in the meaning of religion and how it informs sexual behavior help explain results from the quantitative data. Our results demonstrate the importance of taking a complex religion approach to studying religion and sex-related outcomes

    How Religion, Social Class, and Race Intersect in the Shaping of Young Women’s Understandings of Sex, Reproduction, and Contraception

    No full text
    Using a complex religion framework, this study examines how and why three dimensions of religiosity—biblical literalism, personal religiosity, and religious service attendance—are related to young women’s reproductive and contraceptive knowledge differently by social class and race. We triangulate the analysis of survey data from the Relationship Dynamics and Social Life (RDSL) study and semi-structured interview data from the National Study of Youth and Religion (NSYR) to identify and explain patterns. From the quantitative data, we find that all three dimensions of religiosity link to young women’s understandings of sex, reproduction, and contraception in unique ways according to parental education and racial identity. There is a lack of knowledge about female reproductive biology for young women of higher SES with conservative Christian beliefs (regardless of race), but personal religiosity and religious service attendance are related to more accurate contraceptive knowledge for young black women and less accurate knowledge for young White women. From the qualitative data, we find that class and race differences in the meaning of religion and how it informs sexual behavior help explain results from the quantitative data. Our results demonstrate the importance of taking a complex religion approach to studying religion and sex-related outcomes.https://digitalcommons.snc.edu/faculty_staff_works/1038/thumbnail.jp

    Hypothalamic-Pituitary Disorders in Childhood Cancer Survivors : Prevalence, Risk Factors and Long-Term Health Outcomes

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    CONTEXT: Data on hypothalamic-pituitary (HP) disorders in systematically evaluated childhood cancer survivors are limited. OBJECTIVE: To describe prevalence, risk factors, and associated adverse health outcomes of deficiencies in GH deficiency (GHD), TSH deficiency (TSHD), LH/FSH deficiency (LH/FSHD), and ACTH deficiency (ACTHD), and central precocious puberty (CPP). DESIGN: Retrospective with cross-sectional health outcomes analysis. SETTING: Established cohort; tertiary care center. PATIENTS: Participants (N = 3141; median age, 31.7 years) were followed for a median 24.1 years. MAIN OUTCOME MEASURE: Multivariable logistic regression was used to calculate ORs and 95% CIs for associations among HP disorders, tumor- and treatment-related risk factors, and health outcomes. RESULTS: The estimated prevalence was 40.2% for GHD, 11.1% for TSHD, 10.6% for LH/FSHD, 3.2% for ACTHD, and 0.9% for CPP among participants treated with HP radiotherapy (n = 1089), and 6.2% for GHD, and 30 Gy for ACTHD), alkylating agents (GHD, LH/FSHD), intrathecal chemotherapy (GHD), hydrocephalus with shunt placement (GHD, LH/FSHD), seizures (TSHD, ACTHD), and stroke (GHD, TSHD, LH/FSHD, ACTHD). Adverse health outcomes independently associated with HP disorders included short stature (GHD, TSHD), severe bone mineral density deficit (GHD, LH/FSHD), obesity (LH/FSHD), frailty (GHD), impaired physical health-related quality of life (TSHD), sexual dysfunction (LH/FSHD), impaired memory, and processing speed (GHD, TSHD). CONCLUSION: HP radiotherapy, central nervous system injury, and, to a lesser extent, chemotherapy are associated with HP disorders, which are associated with adverse health outcomes
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